In 1996, he directed a production of Joe Orton's Loot for the Weathervane Theater in Akron.

In 1997 he co-created (with Jay Geldhof and Galen Showman) The Lost, a Harvey-nominated comics mini-series which continued the story of Peter Pan in modern times, with the protagonist presented as an amoral vampiric boy prostitute.[1]

In 2004 he began writing DC Comics' Manhunter series, relaunching it with a third volume, in which he introduced the character of Kate Spencer and her supporting cast. He co-created (with artist Jesus Saiz) Kate Spencer, the title character of the series, the first female character to carry the long-running legacy. He also created Spencer's civilian business partner Damon Matthews, who is in a romantic relationship with superhero Obsidian, one of the few gay-identified couples in mainstream superhero comics.[2] Although #30 was listed as the final issue, the series resumed a year later with Michael Gaydos on art.[3] However, the series was finally canceled with issue #38 in January 2009.[4] Andreyko went to write the Manhunter back-up feature in DC Comics' Batman: Streets of Gotham monthly series that launched in June 2009.

In September 2013, after the creative team of J.H. Williams III and W. Haden Blackman announced their departure from Batwoman, DC co-publisher Dan Didio announced Andreyko as the new ongoing writer of the series starting with issue #25.[7]

In October 2014, Andreyko was announced as the writer of DC Comics series Wonder Woman '77. The series is set within the continuity of the Lynda Carterseries.[8]